1. Field of the Invention
The present invention relates to a private video recorder for recording contents of TV programs delivered from TV stations.
2. Description of the Related Art
The private video recorder is conventionally configured that the contents (video picture) of TV programs are recorded as video picture files in a contents accumulator (recording medium) such as a hard disc drive apparatus, and the contents recorded in the contents accumulator can be edited by cutting, copying, inserting and so on corresponding to operation of an operation apparatus such as a remote control unit by a user. The contents recorded in or edited by the private video recorder can be reproduced on a monitor of a display apparatus connected to the private video recorder, when the data of the video picture file is read out from the contents accumulator.
The private video recorder constantly memorizes the data corresponding to the contents of TV program (hereinafter abbreviated as “contents data”) in a predetermined time period which has been received until the moment in a memory area called “circulation buffer area” in the contents accumulator with no relation to recording of the contents. The contents data, which is temporarily memorized into the circulation buffer area, can be readout from the circulation buffer area until the circulation buffer area is filled by the contents data. Furthermore, new contents data of the TV program just received are serially memorized into the circulation buffer memory, while the contents data already memorized into the circulation buffer area have been readout from the circulation buffer area. By such a configuration, the contents of TV program which has been received can be reproduced as if the contents are paused or rewound.
In the conventional private video recorder, a known file control system such as MS-DOS is used for controlling the video picture files of the contents of TV programs. In the file control system, video data and audio data, which are the substances of the contents data constituting the video picture file, are memorized into and read out from sectors on the recording medium. The sector is the minimum unit of the recording area on the recording medium.
As can be seen from FIG. 10, a memory area of the recording medium is allocated to a control area 91 called “FAT” and a file substance memory area 92 in the file control system of MS-DOS. The control area 91 memorizes control information for controlling the contents data memorized into the file substance memory area 92 as a file. The video data and the audio data, which are the substances of the contents data of the video picture file, are memorized into the file substance memory area 92. The file substance memory area 92 is constituted by a plurality of segments 93. Each segment 93 is further constituted by a predetermined number of the sectors. The segment 93 is the minimum unit for controlling the video picture file, so that the contents data of the video picture file are controlled by the unit of segment 93 in the file substance memory area 92. The control information memorized into the control area 91 includes location information showing positions of the sectors of the segments 93 into which the contents data constituting one video picture file are memorized. The contents data memorized into the segments 93 in the file substance memory area 92 are controlled as one video picture file corresponding to the control information. Each segment 93 is not commonly controlled by a plurality of control information but controlled by only one control information.
When recoding and erasing of the video picture files are repeated in the conventional file control system, the contents data constituting one file are memorized into disintegrative into a plurality of groups of segments 93 which is physically departed from each other. Such a phenomenon is called “fragmentation”. When a video picture file having a larger size is recorded after erasing another video picture file having a smaller size, the contents data of the video picture file having the larger size cannot completely be memorized into the segments into which the contents data of the video picture file having the smaller size was memorized, so that the remainder of the contents data the video picture file having the larger size will be memorized into other segments. As a result, the contents data constituting one file are memorized into disintegrative into a plurality of groups of the segments. In FIG. 10, daubed boxes show the segments into which the contents data constituting the same file are memorized. In the conventional private video recorder, the conventional file control system is used not only for memorizing and reading the contents data of the video picture file of the contents of TV program but also for editing the contents data by such as cutting, copying or inserting.
In the conventional private video recorder, a memory capacity of each segment in the contents accumulator is not so large, so that degree of disintegration that the contents data constituting one file are recorded in disintegrative into a plurality of groups of the segments will be increased by repeating the recording and erasing of the contents of TV programs. When the fragmentation frequently occurs, speed for reading out the contents data of the video picture file from the contents accumulator becomes slower. Reduction of the speed for reading out the contents data of the video picture file causes inadmissible problem in audio-visual equipment that the recording and reproducing of the contents of TV program is paused in midstream.
Furthermore, in the conventional private video recorder, the control information for controlling the contents data of the video picture file has only the location information of the segments into which the contents data constituting the same video picture file are recorded, so that the contents of the video picture file cannot be confirmed until the contents are actually reproduced on the display apparatus by reading out the contents data of the video picture file from the contents accumulator. Thus, it takes much time for reproducing or editing the contents recorded in the conventional private video recorder, so that it is not easy to use.
Still furthermore, in the conventional private video recorder, there is a fear that important contents data are instantly erased from the contents accumulator by inappropriate operation, even though the contents data can be edited by cutting, copying, inserting, and so on. When the contents data memorized into the contents accumulator are once edited, it cannot be turned back. Thus, the conventional private video recorder is not easy to use for editing the contents data of the video picture files.
Still furthermore, in the conventional private video recorder, the contents data temporarily memorized into the circulation buffer area can be read out in repeating. The contents data memorized into the circulation buffer area, however, are erased in order of memorized time when the circulation buffer area is filled. When the contents data are once erased from the circulation buffer area, it is impossible to memorize the contents data into the contents accumulator as the video picture file. For recording the contents of TV program so as to be reproduced at anytime, it is necessary to start to memorize the contents data obtained from the broadcasting signals of the TV program in the contents accumulator simultaneously with the start of on air of the TV program. If the user awakes that the contents of TV program is not recorded due to erroneous operation in midstream of the TV program, it is impossible to memorize the contents data of the contents of TV program from the start of on air.
Still furthermore, in the conventional private video recorder, when no TV program is on air while the private video recorder records the contents of TV program, the contents data corresponding to a noisy picture like sandstorm or a dark picture are memorized into the contents accumulator of the private video recorder, so that the memory capacity of the contents accumulator is fribbled away.
The following documents are known in the art of the present invention.
Publication gazette of Japanese patent application 2001-93264 shows a recording and reproducing apparatus for recording and reproducing video data and audio data by encoding and decoding the signals. The contents recorded in a plurality of discrete memory areas on a disc respectively having relativity are rearranged and rememorized into consecutive areas. By such a configuration, the fragmentation can be resolved. The contents, however, are actually rememorized into the consecutive areas on the disc, so that it needs a lot of time for rememorizing the contents. The contents or other contents cannot be recorded or reproduced while the contents are rearranged and rememorized.
Publication gazette of Japanese patent application 5-308602 shows an image processing apparatus in which data for controlling still image information can be edited. This publication gazette does not refer to the edit of video pictures (contents) of TV programs.
Japanese patent No. 2713163 shows a video recorder in which video data and audio data under nonimage condition or unpronounced condition are replaced by nonimage data code or unpronounced data code, and the replaced data codes are encoded and recoded. By such a configuration, an amount of data can be reduced, so that efficiency of an external memory apparatus can be increased. This patent, however, does not refer to not only recording the contents of TV programs but also editing of files recorded in the memory apparatus.
Publication gazette of Japanese patent application 11-184737 shows a video disc recorder, in which cluster IDs are applied to recording areas and recording information with respect to a disc array, is controlled by using the cluster IDs for preventing the occurrence of the fragmentation by repeating recording and erasing contents of video pictures. This publication gazette, however, does not refer to edit of files recorded in the disc.
Publication gazette of Japanese patent application 2001-8122 shows a digital broadcasting receiver by which TV programs recorded in the past can easily be reproduced. This publication gazette relates to selection of the TV programs and does not relate to the fragmentation, edit and recording of the contents of TV programs.